Setting the Oxidation State of Tc Adsorbed on Pt by X-Ray Photoelectron Spectroscopy

An electrochemical method for the concentration of technetium Tc ions formed by neutron irradiation of a molybdenum target and required for visualization of internal organs in radiopharmaceutical diagnostics has been proposed. Technetium extraction was carried out by electrochemical method. It was found by X-ray photoelectron spectroscopy that the release of technetium at the cathode, due to electrochemical reduction of pertechnetate ions, occurs in the form of TcO⋅xHO. Due to oxidation of surface layers by air oxygen, some amount of Tc(VII) is formed in them: the ratio of Tc(IV): Tc(VII) amounts to 3:7. Under optimal conditions of the process, the efficiency of technetium extraction from the solution containing excess molybdate ions reached 90% during 0.5 h. Since the concentration of molybdenum compounds is small, the reduction of pertechnetate ions occurs with diffusion limitations. The diffusion coefficient of TcO – ions determined by the rotating disk electrode method was 2.14×10 cm s.